Question 2: What is the relationship between subgrade and embankment bed? How to distinguish subgrade means that the soil part of the road includes excavation cutting and filling embankment, and embankment is an artificial subgrade buried after deducting excavation part. Subgrade is subgrade, or subgrade is road trough, on which various pavements can be paved. Subgrade and road groove are basically the same.
Question 3: I'll tell you about the relationship between subgrade, cutting, shoulder, embankment and subgrade, hoping to get your awards.
Subgrade mainly refers to a part of road structure, and road is also a kind of structure, which is divided into three parts: subgrade, base and surface.
Subgrade refers to the lowest part that directly bears the road base and surface course, generally refers to the road foundation of natural foundation or artificial fill, generally composed of soil with good properties or graded sand, and needs to be compacted.
In my impression, cutting should be the saying of excavation section, which generally refers to the subgrade of excavation section, called cutting.
Shoulder, which is common in general roads, refers to the 50cm soil shoulder left on both sides of the road, or the shoulder made of other materials. Its main function is to have a certain effect on the stability of the road surface, and it is curved to facilitate the drainage of the road surface, and to ensure that the mechanical part of the road surface will not be damaged after being washed by rain.
Embankment refers to the road subgrade of the filled section. As opposed to cutting.
Subgrade refers to subgrade, but when we say subgrade, it is more specific, and there should be no substantial difference between subgrade and subgrade.
I hope I can help you. These are all I know. If there is anything wrong, I hope my friends will correct me. Thank you.
Question 4: What is the main body of subgrade? 20-minute subgrade refers to the belt structure built as the pavement foundation according to the location of the line and certain technical requirements, which is the foundation of railways and highways. Subgrade is a linear structure made of soil or stone. Build subgrade under good geological, hydrological and climatic conditions. As far as materials are concerned, subgrade can be divided into three types: soil subgrade, stone subgrade and earth-rock subgrade.
Subgrade body includes embankment filled with natural earth and stone and cutting excavated in natural stratum, and its outline and names of each part are shown in the figure. It directly supports the track and bears the load of the train passing through the track, and is the main body of the subgrade. According to the different geological conditions and filling materials, subgrade body can be divided into six basic forms: embankment, cutting, half-way embankment, half-way embankment and half-way cutting, and subgrade without filling or digging.
Question 5: What do you mean by the ultimate height of the dike? As a system that has been in service for more than ten years, it has ushered in its own home. Now, netizens all over the world can't help but respect this system that has existed tenaciously in Microsoft for more than ten years. Only by continuous exploration, trial and innovation can the system run more humanized. This point is XP can't compare with 7 and 8. 1.
Question 6: What is reverse excavation subgrade? Reverse excavation subgrade:
When the soil quality of subgrade excavation section is not good, and the compaction degree can not meet the requirements after excavation, reverse excavation is adopted, and after excavation, improved soil or other soil that can meet the requirements is used for backfilling. This is the so-called reverse excavation subgrade construction.
First, the noun explanation:
The subgrade construction has reached the design height, but the height of the bottom of the structure is lower than the design height. When excavating the foundation pit of a structure, it is called reverse excavation.
Second, the specific construction method:
1, earthwork excavation and transportation
The earthwork excavation of the foundation in the reaction zone adopts large excavation, and the plane dimensions of excavation are 18.66m (length) *37.8m (width) and 6.4m (length) *2.748m (width). Earthwork excavation adopts the construction method of 220 excavator combined with manual ditch cleaning, and the excavated earthwork is placed beside the foundation pit and transported to the dump truck designated by the owner, with a distance of 3. In the garbage dump, 50 loaders and 220 excavators are used for piling and leveling. When backfilling earthwork, use 220 excavator and dump truck to transport it from the dump designated by the owner to the backfilling area, with a distance of 3.5km. Due to the large amount of earthwork excavation and backfilling, after the earthwork excavation reaches the design elevation, the survey/design unit, the supervision unit, the owner, the general contractor and the construction unit * * * will jointly check the trench, and the construction of the next procedure can be carried out only after each unit is qualified.
2. Foundation positioning and setting out
According to the Code for Engineering Survey (GB50026-2007), the factory survey control points provided by the owner were rechecked, and the secondary control points were introduced into this device. Before the foundation excavation in the reaction zone, our company will send professional survey engineers to locate and set out the foundation, and mark the foundation with white lime at the construction site, and report it to the supervision department for retest and recheck confirmation.
3. Handle the ground-breaking operation ticket.
After foundation positioning, the ground-breaking operation ticket shall be handled two days in advance, and foundation excavation can only be carried out after the site confirmation by the general contractor, supervisor and owner.
4. Personnel preparation
For the smooth implementation of the construction plan, effective quality control and timely completion of the construction task, please refer to the specific personnel, machines and materials of the project management department.
5, the construction process
Determine the excavation sequence and slope → cut out the outline of the groove edge along the gray line → maintain the foundation pit → mark the pile foundation → trim the groove edge by layered excavation → clear the bottom → check and accept → proceed to the next construction.
The gradient value of temporary excavation shall conform to the Code for Acceptance of Construction Quality of Building Foundation Engineering (GB50202-2002).
Question 7: What is subgrade shaping?
A, according to the requirements of design drawings, restore the stakes, and check the position, width, longitudinal slope, transverse slope and corresponding elevation of the subgrade centerline. According to the inspection results, the rectification plan can be prepared and submitted to the supervision engineer for approval before construction.
B, the soil subgrade is scraped or filled manually or mechanically, and it is shaped by mechanical rolling and renovation. When the fill is insufficient or the slope is washed by rain, the original slope will be dug into steps and filled in layers.
C, the surface of soil subgrade shall be leveled by bulldozer. When the shoveled soil is not enough to fill the depression, it shall be filled and compacted with the same soil as the subgrade. Within the range of 15cm of the renovated subgrade surface, loose large stones will be removed and compacted with the same filler as the subgrade.
D, the side ditch renovation should be carried out by hanging the line, and the longitudinal slopes of various ditches should be detected by instruments until the renovation meets the design specification requirements.
E, fill the roadbed on both sides of the overbilling width should be pre-dug. When the slope is short of soil, it must be dug into steps and compacted by layers.
Question 8: What is the difference between subgrade and base in pavement? Is it a concept? It feels like repeating. Subgrade in road engineering includes natural subgrade and artificial subgrade. Subgrade simply means that the pavement layer is called subgrade, including earthwork subgrade, lime-soil subgrade, gravel subgrade, lime-fly ash subgrade and cement stabilized layer. Pavement includes coarse, medium and fine asphalt concrete or cement concrete surfaces. Subgrade and foundation are slightly different in concept.
Question 9: What do you mean by two slopes?
Slope refers to a slope with a certain slope on both sides of subgrade to ensure the stability of subgrade. 1. According to genetic classification: it can be divided into artificial slope and natural slope; 2. According to stratum lithology classification, it can be divided into soil slope and rock slope. Answer: According to the rock structure, it can be divided into: 1 layered structural slope, 2 massive structural slope and 3 reticular structural slope; B: According to the relationship between dip angle and slope direction, it can be divided into: 1 down slope, 2 reverse slope and 3 longitudinal slope. 3. Classification according to service years: It can be divided into permanent slopes and temporary slopes. The engineering protection type of slope is 1. 1 plastered ramming surface [1]1.1Applicable conditions: ① For slopes with soft rock layers (such as argillaceous sandstone, shale, phyllite, argillaceous slate, etc.), ) easy to weather, when the rock weathering is not serious; (2) The protected slope itself must be stable, but its slope shape, steepness and smoothness are not limited; ③ The protected slope must be a dry rock slope without groundwater. Structural requirements of 1. 1.2: ① The plastering thickness is generally 5 ~ 7 cm, and the hammering thickness is 10 ~ 15 cm, which is generally equal thickness. (2) The joints around plastering and stress surface works and unprotected slopes shall be strictly closed. If the intercepting ditch is located at the top of the slope, the bottom and side of the ditch should also be plastered or reinforced for protection. (3) When plastering or tamping a large area, an expansion joint shall be set every 5 ~ 10m. 1.2 Grouting jointing [1] Grouting is suitable for rock cutting slopes with hard rocks, hard weathering, well-developed rock joints and small crack width. Joints are suitable for rock cutting slopes with hard rocks, hard weathering, undeveloped joints and large and deep joints. 1.3 cement-soil slope protection 1.3. 1 Applicable conditions: ① it is suitable for silt, silt, silty clay, clay and other filled slopes. (2) Subgrade fill slope that is easy to be flooded. ③ It can be used in saline soil area.
Problem 10: Road subgrade and shoulder problems. What do you mean by Pei Shoulder? It is suggested that you calculate the shoulder width 2x 1.75m, but the roadbed width of 6.00m you pointed out does not match.
In the process of repairing the pavement, firstly, soil is piled on both sides of the pavement, that is, the common saying "ploughing road groove", and then the pavement material is spread and rolled, and the road groove is ploughed to the pavement design elevation layer by layer. This process is actually cultivating the shoulder, which is measured in m2 in the budget quota, and there is no earthwork for cultivating the shoulder in the quota, so the earthwork quantity to be backfilled must be given.